A radar system is composed of a plurality of components, whereby the components can exhibit some degree of non-ideal behavior, which can influence a purity or quality of a signal being processed by the radar system. Such components often exhibit non-linear behavior and/or other imbalances. In range-Doppler radar data, the effects of the non-linear behavior can be manifested as spurious signals, also known as “spurs”. The spurs can lead to false indication of a target energy, thereby reducing the performance, accuracy, reliability, and/or general utility of the radar system.
Radar modes and systems that utilize range-Doppler radar data, and hence are subject to such performance degradation, include Synthetic Aperture Radar (SAR), Inverse-SAR (ISAR), Moving Target Indicator (MTI), Wide Area Search (WAS), etc.
In addition, imbalance in the channels of a quadrature demodulator can lead to ghosting that may also be characterized as spurious energy. Such quadrature demodulators may be employed more broadly than just for generating range-Doppler radar data.
A conventional approach for spur mitigation is to pay attention to component selection, circuit construction, circuit layout, and circuit fabrication to minimize the susceptibility to spur creation. Thereafter, heuristic techniques can be utilized to desensitize the radar to offending spurs. However, spurs can survive these measures, and may be of sufficient energy to render false targeting, alarms, etc.
Hence, even though electrical components continue to be developed that are stable over temperature and time, with an according expense, spurs can still be generated and added to a signal, leading to false targeting.